Electrosurgical instrument

ABSTRACT

An electrosurgical instrument includes an elongated housing having proximal and distal ends. The proximal end is configured to couple to a source of electrosurgical energy via first and second channels extending along a length of the housing to the distal end thereof. The distal end includes a reflector having a dielectric load operably coupled thereto and configured to receive at least a portion of the first conductor therein. In a first mode of operation, electrosurgical energy is transmitted to the first channel and reflected from the reflector to electrosurgically treat tissue. The reflector is configured to receive at least a portion of the second channel therein. In a second mode of operation, electrosurgical energy is transmitted to the second channel to dissect tissue.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 14/954,996, filed on Nov. 30, 2015, which is acontinuation application of U.S. patent application Ser. No. 14/564,896,filed on Dec. 9, 2014, now U.S. Pat. No. 9,198,721, which is acontinuation application of U.S. patent application Ser. No. 13/477,320,filed on May 22, 2012, now U.S. Pat. No. 8,906,008, the entire contentsof each of which are incorporated herein by reference.

BACKGROUND

Technical Field

The present disclosure relates to an electrosurgical instrument. Moreparticularly, the present disclosure relates to a directional microwaveenergy instrument configured to electrosurgically treat tissue in twomodes of operation; a first mode of operation to electrosurgically treattissue; and a second mode of operation to dissect the tissue.

Description of Related Art

Standard surgical procedures for trauma, cancer and transplants in thekidney, liver, and like organs have several key shortcomings affectingefficacy, morbidity and mortality. In an effort to fully remove orresect an organ, the surgeon may be forced to breach the tissue causinga large amount of bleeding. Careful hemostasis can minimize blood lossand complications but is laborious and time consuming using the systemsand methods known in the art. Uncontrollable bleeding, for example, isone of the leading causes that prevent such treatments from beingoffered to patients with cirrhotic livers.

Typical methods for creating resections and/or controlling bleeding andblood loss include scalpels, electrocautery, ultrasonic scalpels, argonbeam coagulators, and radio frequency (RF) surface dissectors.Typically, a surgeon utilizes one of the aforementioned therapies, e.g.,a scalpel, for creating resections and another one of the aforementionedtherapies, e.g., an argon beam coagulator, to control bleeding. Thesetherapies, however, in their present form have one or more potentialdrawbacks, such as, for example, a complete lack or partial inability tocreate a hemostatic or near-hemostatic resection plane with anysignificant depth (e.g., the devices utilized to control bleeding,typically, create a small footprint).

SUMMARY

As can be appreciated, a directional microwave and radio frequencyenergy instrument that is configured to electrosurgically treat tissuein two modes of operation to resect and dissect tissue may prove usefulin the medical arts.

Embodiments of the present disclosure are described in detail withreference to the drawing figures wherein like reference numeralsidentify similar or identical elements. As used herein, the term“distal” refers to the portion that is being described which is furtherfrom a user, while the term “proximal” refers to the portion that isbeing described which is closer to a user.

An aspect of the present disclosure provides an electrosurgicalinstrument. The electrosurgical instrument includes an elongated housinghaving proximal and distal ends. The proximal end configured to coupleto a source of electrosurgical energy via first and second channelsextending along a length of the housing to the distal end thereof. Thedistal end including a reflector having a dielectric load operablycoupled thereto and configured to receive at least a portion of thefirst channel therein. In a first mode of operation electrosurgicalenergy is transmitted to the first channel and reflected from thereflector to electrosurgically treat tissue. The reflector is configuredto receive at least a portion of the second channel therein. In a secondmode of operation electrosurgical energy transmitted to the secondchannel to dissect tissue. The reflector may be formed from a conductivemetal tube having a diagonal cross-cut at least partially through awidth thereof.

The dielectric load may be shaped to complement a shape of thereflector. The dielectric load may be made from a material including,but not limited to ceramic, fluid and plastic. The dielectric load mayinclude at least one aperture therein that is configured to receive atleast a portion of the coaxial feed therein.

In certain instances, the first channel is in the form of a coaxial feedthat includes an outer conductor, a dielectric extending past the outerconductor and an inner conductor extending past both the outer conductorand dielectric. In this instance, the inner conductor does not extendpast the reflector.

In certain instances, the second channel may be in the form of anelectrical lead including a monopolar electrode. In this instance, themonopolar electrode may be disposed at a distal tip of the reflector.

In certain instances, the electrosurgical instrument may also include amicrowave block that is operably coupled to the distal end of theelectrosurgical instrument adjacent the dielectric load. In thisparticular instance, the microwave block includes a dielectric distalportion and a conductive proximal portion. The microwave block may beconfigured to prevent electrosurgical energy from exiting a distal sideof the reflector when the electrosurgical instrument is in the firstmode of operation. The dielectric portion of the microwave block mayinclude a dielectric constant that is less than a dielectric constant ofthe dielectric load of the distal end.

In certain instances, the electrosurgical instrument may also include aswitch assembly that is supported on the housing and configured to placethe electrosurgical instrument into the first and second modes ofoperation.

In certain instances, the electrosurgical instrument may also include acooling assembly that operably couples to the electrosurgical instrumentand circulates at least one coolant through the electrosurgicalinstrument to prevent the reflector and electrode from exceeding apredetermined temperature.

In certain instances, the electrosurgical instrument may also a sensorassembly that is configured to detect when the electrosurgicalinstrument contacts tissue. In this instance, the sensor assembly may bean optical sensor assembly, electrode impedance sensor assembly andacoustic transducer response assembly.

An aspect of the present disclosure provides an electrosurgicalinstrument. The electrosurgical instrument includes an elongated housinghaving proximal and distal ends. The proximal end is configured tocouple to a source of electrosurgical energy via first and secondchannels extending along a length of the housing to the distal endthereof. A switch assembly is supported on the housing and is configuredto place the electrosurgical instrument into first and second modes ofoperation. A reflector operably disposed at the distal end of thehousing has a tapered configuration and is configured to provide anenergy pattern in tissue proportional to a depth of the taper of thereflector. A dielectric load is shaped to complement a shape of thereflector for coupling the dielectric load to the reflector. Thedielectric load is configured to receive at least a portion of the firstchannel therein. In the first mode of operation electrosurgical energytransmitted to the first channel is reflected from the reflector toelectrosurgically treat tissue. The reflector is configured to receiveat least a portion of the second channel therein. In the second mode ofoperation electrosurgical energy transmitted to the second channel todissect tissue.

The dielectric load may be made from a material including, but notlimited to ceramic, fluid and plastic. The dielectric load may includeat least one aperture therein that is configured to receive at least aportion of the coaxial feed therein.

In certain instances, the first channel may be in the form of a coaxialfeed that includes an outer conductor, a dielectric extending past theouter conductor and an inner conductor extending past both the outerconductor and dielectric. In this instance, the inner conductor does notextend past the reflector.

In certain instances, the second channel may be in the form of anelectrical lead including a monopolar electrode. In this instance, themonopolar electrode may be disposed at a distal tip of the reflector.

In certain instances, the electrosurgical instrument may also include amicrowave block that is operably coupled to the distal end of theelectrosurgical instrument adjacent the dielectric load. In thisparticular instance, the microwave block includes a dielectric distalportion and a conductive proximal portion. The microwave block may beconfigured to shape electrosurgical energy exiting a distal side of thereflector and improve efficiency of the electrosurgical instrument whenthe electrosurgical instrument is in the first mode of operation. Thedielectric portion of the microwave block may include a dielectricconstant that is less than a dielectric constant of the dielectric loadof the distal end.

BRIEF DESCRIPTION OF THE DRAWING

Various embodiments of the present disclosure are described hereinbelowwith references to the drawings, wherein:

FIG. 1 is a schematic view of an electrosurgical system configured foruse with an electrosurgical instrument according to an embodiment of thepresent disclosure;

FIG. 2 is a schematic, exploded view of a distal end of theelectrosurgical instrument depicted in FIG. 1 showing componentsseparated;

FIG. 3 is a schematic, side view of a coaxial feed and dielectricmaterial of FIG. 2 in an assembled configuration;

FIG. 4 is a schematic, side view of the coaxial feed, dielectricmaterial and a reflector of FIG. 2 in an assembled configuration;

FIG. 5a is a schematic, proximal view of an optional microwave balunthat may be utilized with the electrosurgical instrument depicted FIG.1;

FIG. 5b is a schematic, cross-sectional view of the microwave balundepicted in

FIG. 5 a;

FIG. 6 is a schematic, side view of the distal end of theelectrosurgical instrument depicted FIG. 1 with the microwave balundepicted in FIGS. 5a and 5b operably coupled thereto; and

FIG. 7 is a schematic, bottom view of the reflector depicted in FIG. 2.

DETAILED DESCRIPTION

Detailed embodiments of the present disclosure are disclosed herein;however, the disclosed embodiments are merely examples of thedisclosure, which may be embodied in various forms. Therefore, specificstructural and functional details disclosed herein are not to beinterpreted as limiting, but merely as a basis for the claims and as arepresentative basis for teaching one skilled in the art to variouslyemploy the present disclosure in virtually any appropriately detailedstructure.

As noted above, it may prove useful in the medical field to provide adirectional microwave and radio frequency energy instrument that isconfigured to electrosurgically treat tissue in two modes of operationto resect and dissect tissue. In accordance with the instant disclosure,an electrosurgical instrument that couples to an electrosurgical energysource is configured to function in two or more modes of operation, afirst mode that provides microwave energy to coagulate tissue (e.g.,control bleeding) and a second mode that provides radio frequency energyto dissect the coagulated tissue (e.g., create a resection). Theelectrosurgical device in accordance with the instant disclosure allowsa surgeon to perform both of these procedures with a single instrument.

Turning now to FIG. 1, an electrosurgical system 2 is illustratedincluding an electrosurgical energy source, e.g., a generator 4, and anelectrosurgical instrument 6 in accordance with the instant disclosure.

Generator 4 is configured to generate electrosurgical energy in the formmicrowave energy and radio frequency energy. In embodiments, thegenerator 4 may be configured to also generate ultrasonic energy,thermal energy, etc. In accordance with the instant disclosure,frequencies of operation of the generator 4 range from about 915 MHz toabout 8000 MHz. Other frequencies of operation of the generator 4 may bebelow 915 MHz and above 8000 MHz. One or more switches or buttons 8(shown in phantom in FIG. 1) may be provided on the generator 4 to allowa surgeon to switch between first and second modes of operation.Alternately, and as in the illustrated embodiment, the electrosurgicalinstrument 6 may include one or more switches 10 (FIG. 1) thereon toallow a surgeon to switch between first and second modes of operation.Or, in certain instances, a footswitch (not explicitly shown) inoperative communication with the generator 4 and/or the electrosurgicalinstrument 6 may be utilized to provide the aforementioned switchingcapabilities.

Electrosurgical instrument 6 includes a housing 3 having proximal anddistal ends 5 and 7, respectively (FIG. 1). Housing 3 may be made fromany suitable material including metal, plastic composite, ceramic, etc.In the illustrated embodiment, housing 3 is made from plastic composite.Housing 3 supports switching assembly 10 (and operative componentsassociated therewith) thereon to provide the electrosurgical instrument6 with hand-held capabilities, e.g., hand-held switching capabilities(FIG. 1).

Switching assembly 10 includes push-buttons 10 a and 10 b thatrespectively place the electrosurgical instrument 6 into the first andsecond modes of operation upon activation thereof.

Continuing with reference to FIG. 1, a cable 12 or the like couples thegenerator 4 to a housing 3 of the electrosurgical instrument 6 toprovide electrosurgical instrument 6 with the capability of operating inthe first and second modes of operation. To this end, cable 12 couplesto proximal end 5 of housing 3 and includes a first channel in the formof a coaxial feed 14 and a second channel in the form of an electricallead 16 (FIG. 2).

Coaxial feed 14 is received at the proximal end 5 (FIG. 1) of thehousing 3 for providing microwave energy thereto and includes an outersheath (not explicitly shown), an outer conductor 18, a dielectric 20that extends past the outer conductor and an inner conductor 22 thatextends past both the outer conductor 18 and dielectric 20, as best seenin FIG. 2. This configuration of the coaxial feed 16 facilitatescoupling the coaxial feed 14 to a dielectric load 24 (FIG. 2), as willbe described in greater detail below.

Electrical lead 16 is received at the proximal end 5 (FIG. 1) of thehousing 3 for providing radio frequency energy thereto and includes oneor more electrodes, e.g., one or more monopolar electrodes 26, at adistal end thereof (FIG. 2).

Both of the coaxial feed 14 and electrical lead 16 extend along a lengthof the electrosurgical instrument 6 for coupling to the dielectric load24 and a reflector 28, respectively (FIG. 2).

Referring to FIG. 2, dielectric load 24 is illustrated. Dielectric load24 may be made from any suitable dielectric material including, but notlimited to ceramic, plastic composite, fluid, etc. In the illustratedembodiment, dielectric load 24 is made from ceramic. Dielectric load 24is shaped to complement the reflector 28 to facilitate coupling thedielectric load 24 to the reflector 28 during the manufacturing processof the electrosurgical instrument 6. The dielectric load 24 is coupledto the reflector 28 via one or ore suitable coupling methods. In theillustrated embodiment, a friction-fit or press-fit is utilized tocouple the dielectric load 24 to the reflector 28. In particular, thereflector 28 includes a generally tubular configuration with a diameterthat allows the dielectric load 24 to slide into the reflector 28 suchthat the dielectric load 24 is secured to the reflector 28.

Dielectric load 24 includes a substantially solid configuration with anaperture 30 that is sized to receive the dielectric 20 and the innerconductor 22 therein, see FIGS. 2 and 3. In an assembled configuration,the dielectric 20 and inner conductor 22 are slid into the reflector andpositioned adjacent a tapered, diagonal cut that extends along a distalface 32 of the reflector 28 (FIGS. 2-4 and 6). Positioning the innerconductor 22 at this location within the reflector 28 provides an energypattern that is as long as the tapered distal face of the reflector 28,as best seen in FIG. 6.

Reflector 28 may be made from any suitable conductive material and, asnoted above, includes a generally tubular configuration. In theillustrated embodiment, reflector 28 is made from metal that exhibitsreflective properties to reflect the microwave energy in accordance withthe instant disclosure. A tapered, diagonal cross-cut is providedthrough a width of the reflector 28 at the distal face 32 thereof. Anangle of the cross-cut may be altered to achieve specific energypatterns that are reflected from the reflector 28 to electrosurgicallytreat tissue. In some embodiments, the reflector 28 may be configured toprovide an energy pattern in tissue that is proportional to a depth ofthe taper of the reflector 28. Further, in certain instances, the distalface 32 may be selectively coated with conductive patterning tofacilitate dissecting tissue during the second mode of operation.

Reflector 28 is configured to receive the electrical lead 16 includingmonopolar electrode(s) 26 therein, e.g., through an aperture (notexplicitly shown) that extends through the reflector 28, such that themonopolar electrode(s) 26 is positionable adjacent a distal tip of thereflector 28 to emit radio-frequency energy to dissect tissue in thesecond mode of operation. Electrode(s) 26 may be secured within theaperture and to the reflector 28 via a press-fit, friction-fit, adhesiveor other suitable coupling method.

Reflector 28 may be configured for coupling to the housing 3 by anysuitable methods. In the illustrated embodiment, the reflector 28 isovermolded to the housing 3. Alternately, the reflector 28 may bepress-fit or friction-fit to the housing 3, or an adhesive may beutilized to couple the reflector 28 to the housing 3.

In embodiments, an optional microwave balun, e.g., a microwave block,choke short, impedance matching network of the like, (FIGS. 5A and 5B)may be operably coupled to a proximal end of the reflector 28 adjacentthe dielectric load 24 (FIG. 6). In the illustrated embodiment, themicrowave balun is in the form of a microwave block 34 that isconfigured to keep electrosurgical energy from exiting a distal side ofthe reflector 28 and control a shape of the radiating field emitted fromreflector 28. Microwave block 34 may be configured to a fraction numberof wavelengths, e.g., 214 wavelength. Microwave block 34 includes agenerally elongated, annular configuration having a distal dielectricportion 36 and a proximal conductive portion 38 (see FIGS. 5A-5B).Distal dielectric portion 36 includes a dielectric that is lower thanthe dielectric load 24 and includes a higher loss factor than thedielectric load 24. In an assembled configuration the coaxial feed 14 isfeed through the microwave block 34 such that the outer conductor 18 isin electrical communication with the proximal conductive portion 38, asbest seen in FIG. 6. Configuring the distal dielectric portion 36 inthis manner facilitates reducing the overall quality factor “Q” of theelectrosurgical instrument 6.

Operation of the electrosurgical instrument 6 is described in terms of aliver resection. In use, electrosurgical instrument 6 is positionedadjacent tissue of interest, e.g., liver tissue. A surgeon may coagulatethe tissue via pressing the push-button 10 a to place the generator 4 inthe first mode of operation. The microwave energy transmitted to theinner conductor 22 is reflected from the reflector 28 toelectrosurgically treat the tissue. The reflective microwave energyprovides a precise “footprint” on tissue, e.g., deeply penetratestissue. The depth that the microwave energy penetrates tissue isdetermined by, inter alia, the angle of the distal face 32, frequency ofoperation and/or the power level that the generator 4 is set to.

A surgeon may, subsequently, dissect the electrosurgically treatedtissue via pressing the push-button 10 b to place the generator 4 in thesecond mode of operation. The microwave energy transmitted to theelectrode(s) 26 is emitted therefrom to electrosurgically treat thetissue.

The electrosurgical instrument 6 overcomes the aforementionedshortcomings that are typically associated with conventional therapiesfor resection and dissecting tissue. That is, a surgeon can quickly andeffectively resect and dissect tissue with a single instrument. As canbe appreciated, this decreases blood loss and the time a patient needsto be under anesthesia during a resection and/or dissection procedure.

From the foregoing and with reference to the various figure drawings,those skilled in the art will appreciate that certain modifications canalso be made to the present disclosure without departing from the scopeof the same. For example, in certain embodiments, a cooling assembly 50(shown in phantom in FIG. 1) may be operably coupled to theelectrosurgical instrument 6 and configured to circulate at least onecoolant through the electrosurgical instrument 6 to prevent thereflector 28 and/or electrode(s) 26 from exceeding a predeterminedtemperature.

In certain instances, the electrosurgical instrument 6 may also includesurface contact detection capabilities configured to ensure that theelectrosurgical instrument 6 is in adequate contact with tissue prior toenabling microwave and/or radio frequency energy to treat tissue.Surface contact capabilities may be provided by any suitable methods,such as, for example, a sensor assembly 52 (FIG. 1 shows a sensorassembly 52 in phantom for illustrative purposes) that is configured todetect when the electrosurgical instrument 6 contacts tissue. In thisinstance, the sensor assembly 52 may include one or more sensors (orcombination of sensors) including, but not limited to, an optical sensorassembly, electrode impedance sensor assembly and acoustic transducerresponse assembly, etc.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of particular embodiments. Those skilled in the artwill envision other modifications within the scope and spirit of theclaims appended hereto.

1. (canceled)
 2. A method of assembling an electrosurgical instrument,comprising: disposing a balun about a distal end portion of a coaxialfeed that is configured to couple to a source of electrosurgical energy;and operably coupling an electrically conductive reflector to the distalend portion of the coaxial feed, the reflector configured to radiateelectrosurgical energy provided by the coaxial feed to treat tissue. 3.The method according to claim 2, further comprising sliding the coaxialfeed into the reflector.
 4. The method according to claim 2, furthercomprising positioning an inner conductor of the coaxial feed and adielectric of the coaxial feed adjacent a diagonal surface of thereflector.
 5. The method according to claim 4, further comprisingcoating the diagonal surface with conductive patterning.
 6. The methodaccording to claim 2, further comprising coupling a dielectric load tothe distal end portion of the coaxial feed.
 7. The method according toclaim 6, further comprising disposing the distal end portion of thecoaxial feed in an aperture defined in the dielectric load.
 8. Themethod according to claim 6, further comprising disposing the dielectricload in a channel defined in the reflector.
 9. The method according toclaim 2, further comprising disposing a monopolar electrode at a distalend portion of the reflector.
 10. The method according to claim 2,further comprising electrically coupling a conductive portion of thebalun to an outer conductor of the coaxial feed.
 11. The methodaccording to claim 2, further comprising sliding the coaxial feedthrough the balun.
 12. A method of assembling an electrosurgicalinstrument, comprising: coupling a dielectric load to a distal endportion of a coaxial feed; and coupling an electrically conductivereflector to the dielectric load, the reflector configured to reflectelectrosurgical energy provided by the coaxial feed to treat tissue. 13.The method according to claim 12, further comprising disposing thedistal end portion of the coaxial feed in an aperture defined in thedielectric load.
 14. The method according to claim 12, furthercomprising disposing the dielectric load in a channel defined in thereflector.
 15. The method according to claim 12, further comprisingpositioning an inner conductor of the coaxial feed and a dielectric ofthe coaxial feed adjacent a diagonal surface of the reflector.
 16. Themethod according to claim 15, further comprising coating the diagonalsurface with conductive patterning.
 17. The method according to claim12, further comprising disposing a monopolar electrode at a distal endportion of the reflector.
 18. The method according to claim 12, furthercomprising operably coupling a microwave block to a proximal end portionof the reflector.
 19. The method according to claim 18, furthercomprising sliding the microwave block into the proximal end portion ofthe reflector.
 20. The method according to claim 18, further comprisingsliding the coaxial feed through the microwave block.
 21. The methodaccording to claim 18, wherein a dielectric portion of the microwaveblock includes a dielectric constant that is less than a dielectricconstant of the dielectric load.